Automatic heat regulating system



@ct 9 1935- D. H. KINNAN AUTOMATIC HEAT REGULATING SYSTEM Filed' March7, 1952 /NVEN770R YTENE vs W1} TNESS Patented Oct. 8, 1935 UNETED STATESPATENT OFFICE Lennox Furnace Company,

1110., Syracuse,

N. Y., a corporation of New York Application March 7, 1932, Serial No.597,236

4 Claims.

This invention relates to new and useful improvements in automatic heatregulating systems adapted to be used in connection with boilers,furnaces, etc., and in which a thermostat control switch is electricallyconnected with a pair of control valves associated with the fuel supplyconduit for governing the supply of fuel to the burner.

This invention relates more particularly to an automatic control forheat-producing systems adapted to burn natural or manufactured gas, asfuel, and wherein the main fuel supply conduit is provided with anautomatic control valve and a by-pass extending around the valve havinga second valve therein also automatically controlled for governing theflow of fuel therethrough.

The main object of this invention is to produce a simple, durable andefficient means for automatically controlling the opening and closing ofthe main fuel supply valve and the by-pass conduit valve independentlyof each other.

Another object is to provide for automatic closing of both gas valves incase electric current is discontinued or the pilot burner fails tofunction.

Other objects and advantages relating to the structure and the functionand arrangement of the parts thereof, will more fully appear in thefollowing description, taken in connection with the accompanying drawingin which:-

Figure l is a diagrammatic view illustrating a complete control systemembodying the various features of this invention.

Figure 2 is a partial sectional view illustrating diagrammatically themanner in which the pilot safety control is associated with the pilotburner.

My novel temperature control system, as illustrated in the drawing,consists of a thermostat control switch member I, a main fuel supplyconduit 2 connected with a burner 3 and having a control valve 4connected therewith, and a bypass conduit 5 connected with the mainconduit 2 at opposite sides of the valve 4 to extend around said valveand having a control valve 5 connected therein.

Each of the valves 4 and t have operably connected therewith arespective actuating motor I and 8 which have associated therewithsuitable electric control circuits which are also connected with thethermostatic control switch I whereby the motors and valves may beautomatically controlled under varying degrees of temperatureindependently of each other, as will hereinafter more fully appear.

The burner 3 may be of any desired type which, as illustrated in thedrawing, is adapted to burn natural or manufactured gas and which ismounted in any well-known manner in a suitable fur-nace or boilerindicated at ill. The main fuel supplyconduit 2 may be connected with asuitable source -of fuel supply such as a gas main, not 5 shown, andextends through the wall of the furnace I B and is operably connectedwith the burner '3 in the usual manner.

Thecontrol valve -4connected in the ,main supply conduit 2 may be of anywell-known type of 10 self-closing valves and which, as indicated,consists of a valve member "H normally maintained in closed positionupon the seat I2 by a spring H3. The by-pass 5, as before stated, isconnected with the main conduit 2 at opposite sides of the valve 4 andis of less cross-sectional area than the main conduit '2 so-that asmaller quantity of fuel is permitted to pass through the by-passconduit than through the-main'conduit 2 when the valves 4 and 6 are inthe open position.

The -bypass valve '6 is of the same springactuated type as the mainconduit valve 4 and has the valve stem l5 thereof operably connectedwith the motor 8 in any suitable manner and which, in this instance,consists of an actuating disk Ni'having a drive pin I! connectedtherewith adapted to engage a lateral projecting lug it provided on thevalve stem I5 for'moving the valve stem 15 and valve ll to the openposition against the action-of the spring [3.

The disk It may be driven by the motor 8 through the medium of a trainof gears, not shown, or may, as illustrated in the drawing, be connecteddirectly with the armature shaft 20 of the motor "8. Similarly, thevalve stem 22 of the valve 1 may be actuated by the motor "i by means ofa disk 23 having a drive pin 2 adapted to engage a laterally extendinglug 25 provided on the valve stem 22.

The disk 23 like the disk l6 for the valve 6 may be actuated by themotor 7 through the medium of a train of gears, or said disk may beconnected directly with the armature shaft 26 of the motor I so thatwhenthe motor '5 is actuated by a current passing therethrough, the valvemember I i will be moved from the seat I2 against the action of thespring 13 to the open position, the motors l and 8 each being soconstructed that when the respective valve members are moved to the openposition, they will be maintained in said position against the action ofthe respective springs until such time as the circuit passing throughthe motor is broken, whereupon the respective valves will be returned tothe closed position by the corresponding springs.

The thermostatic control switch I may be of any well-known type andwhich, in this instance, consists of a base 28, as indicated by dottedlines in the figure, and upon which is operably mounted a thermostaticelement 29 connected at one end with an adjustable support 30 mounted onthe base 28 and having secured to the other end thereof, a plurality of,in this instance three, swinging contact blades 3 I, 32 and 33.

The contact blades 3|, 32 and 33 are each composed of suitable material,such as brass, adapted to easily conduct electricity, and the blades 32and 33 are formed from relatively thin metal so as to be easily flexedwhile the blade 3| is composed of a heavier piece of metal so as to beless flexible than the blades 32 and 33. Each of these blades isprovided with a respective contact point 34, 35 and 35 adapted to co-actwith corresponding contact screws 31, 38 and 39 which are adjustablymounted in respective posts 40, 4| and 42, which are mounted ininsulated relation upon the base 28.

The electric circuit connecting the motors 1 and 8 with the thermostaticcontrol switch consists, in this instance, of a transformer 45 havingthe primary winding 46 thereof connected by wires 41 with any suitablesource of potential not shown, and the secondary winding 48 has thepositive side thereof connected by a conductor 49 with a terminal 58mounted on a switchboard 5|, indicated by dotted lines, and which may bemounted in any suitable location, preferably near the motor The motor 1has one terminal thereof connected by a conductor 52 with the terminal50 and the other terminal connected by a conductor 53 with a secondterminal 54 also connected with the switchboard 5| and which iselectrically connected by a conductor 55 to a terminal 56 provided onthe base 28 of the thermostatic switch the terminal 56 beingelectrically connected by a conductor 51 with the contact screw 31.

The positive side of the secondary coil of the transformer 45 is alsoelectrically connected with the motor 8 through the medium of aconductor 59 which has one end thereof connected with the terminal 50 onthe switchboard 5| and the other end connected with a terminal 60provided on a switchboard 5| indicated by dotted lines, and which ispreferably mounted in a convenient locality near the motor 8.

The motor 8 has one terminal thereof connected by a wire 62 with theterminal 60, while the other terminal of the motor 8 is connected by awire 63 with a terminal 64 provided on the switchboard BI and which iselectrically connected by a conductor 65 with a terminal 65 secured tothe base 28 of the thermostatic control switch and which, in turn, iselectrically con nected by a conductor 66 with the contact screw 38.

The contact screw 39 on the thermostatic control switch in thisinstance, is connected with the negative side of the secondary coil 48of the transformer 45 by means of a terminal bar 68 which is connectedby a conductor 69 with a terminal 10 mounted on the base 28 of theswitch The terminal 10 is connected by a conductor H with a terminal 12mounted on the switchboard BI and which is electrically connected by aconductor plate 13 with a terminal 14 also mounted on the switchboard6|. This terminal 14 is connected by a conductor 75 with a terminal 16mounted on the switchboard 5| and which, in turn, is connected by aconductor 11 with the negative side of the secondary coil of thetransformer 45.

The armature shaft 23 for the motor 8 is provided with a cam 19 which,during the initial movement of the motor 8, is adapted to close a 5switch 8|) which has one terminal thereof connected by a switch bar 8|with the terminal 54 on the switchboard El and the other terminalelectrically connected by a conductor 82 with a terminal 83 mounted onthe base 28 of the control 10 switch and which is in electricalconnection with the supporting member 33 for the thermostatic element29.

Each of the valves 4 and 6 may, when desired, be manually opened and bemaintained in the 15 open position, if for any reason the current forthe motors and 8 is discontinued, and which mechanism for the valves 4for instance, consists of an extension 85 having one end secured to thevalve stem 22 and the other end thereof provided 20 with an elongatedslot 86 through which is slidably mounted a switch-actuating member 3'!slidably mounted on the switchboard 5|.

The outer end of the switch-actuating member 81 is provided with a camface 88 adapted to en 25 gage the outer end of the slot 85 for movingthe extension 85 and valve stem 22 outwardly against the action of thespring l3 as the switch-actuating m mber 81 is moved inwardly. As themember 81 approaches its innermost position, the end 30 of the extension85 engages a recess 89 provided in the member 81 adjacent the cam face88 so that the valve M will be thereby maintained in the open positionby the actuating member 8?, while said actuating member will bemaintained 35 against outward movement by the extension 85 engaging saidrecess 89.

The opposite or inner end of the switch-actuating member 81 isassociated with a movable con tact bar 90 of a switch member 9!, saidbar hav- 40 ing one end thereof secured to the terminal 54 mounted onthe switchboard 5|, while the other end of the bar is adapted to bemoved into electrical connection with a switch contact member 92 of theswitch 9| and which is secured to a 5 terminal 93 electrically connectedby a conductor bar 94 with the terminal 16.

The mechanism by which the by-pass valve 6 may be manually controlled,as before stated, is similar to the mechanism for the valve 4 and 5consists of an extension 96 having one end connected with the valve stem5 and the other end having a slotted connection with theswitch-actuating member 91 slidably mounted on the switchboard Bl. Thisswitch-actuating member 91 is 55 also provided with a cam face 88 and arecess 99 similar to the cam 88 and recess 89 of the switch-actuatingmember 81.

The inner end of the switch-actuating member 91 terminates in juxtaposedrelation with a switch 0 member I30 which has a movable contact bar |0|secured to the terminal 64 and adapted to be moved by theswitch-actuating member 97 into contact with a fixed contact bar I32which is electrically connected with the terminal 72. 55

The burner 3 is provided with a pilot burner which is provided with asupply conduit I05 connected with the main conduit 2 at the inlet sideof the valve 4, and in order that no fuel as gas will be fed to theburner 3 if for any reason 70 the pilot light should be extinguishedwhile the heating system is being automatically controlled, I haveprovided a pilot safety control indicated at ||0 which is connected inseries with the transformer 45 and motors and 8. 75

This pilot safety control III! may be of any suitable construction andas illustrated more clearly in Figure 2, consists of a thermostaticelement III positioned in close relation to a series of fine apertures II2 provided in the pilot burner tube through which the fuel escapes toform a blaze for heating the element II I. This element III is connectedby a rod I I3 to a normally open switch II so that when the'element isheated, the switch is closed by the action of the element for closingthe energizing circuit for motors i and 6. It is thus seen that in casethe pilot light should be extinguished, the circuit passing through thesafety pilot switch I I l will be broken permitting the valves I I foreach of the fuel control valves 4 and E to be returned to their closedposition by the respective springs I3 in case said valves are in theopen position, thereby shutting off the supply of fuel to the burner 3and prevent the possibility of an explosion of gases which otherwisemight accumulate in the furnace or heater.

In operation, the blades of the thermostatic control switch I may beadjusted in any wellknown manner, not herein necessary to illustrate ordescribe by the manipulation of the contact screws 3?, 38 and 39 and byadjusting the supporting member 39 for the thermostatic element 29 sothat the swinging blade 33 will be in electrical contact with thecontact screw 38 when the temperature in the room or building is at apredetermined desired degree according to the setting of thethermostatic control switch.

The bar 32 and contact screw 39 are so related that they will be inelectrical connection while the temperature is at the desired degree andwill break the circuit therethrough when the temperature rises to acertain amount, say two degrees above the desired normal temperature,while the contact bar 3i and contact screw 3? will be normallymaintained out of electrical connection and will only come intoelectrical connection when the temperature drops a certain amount, saytwo degrees below the normal or desired temperature.

Assuming now, that the thermostat control switch has been set tomaintain a normal temperature of say seventy degrees, in which case thecontact bars 32 and 33 will be in electrical connection with therespective contact screws 38 and 39 when the room temperature is atseventy degrees and the contact bar 3I will be out of electricalconnection with its contact screw 31, under which condition the mainsupply conduit valve 9 will be maintained in its closed position by thespring I3 due to the circuit passing from the transformer 45 through theconductors t9 and 52, the motor I, and conductors 53, 55 and 5? beingbroken at the end of the screw 31. The valve 6, however, in the by-pass5 will be maintained in the open position due to the current passingfrom the transformer 45 through the conductors 39, 59 and 62, thencethrough the motor 8 and conductors 63, 65 and 66 to the contact screw 38and thence through the swinging blade 33 of the control switch I to theblade 32 and thence out through the contact screw 39 and terminal bars88 to the conductors I59 and II to the terminal I2 and thence throughthe conductor bar I3 and conductors I5 and I? to the transformer 65.

This maintaining of the valve 4 in the closed position and the valve 6in the open position will permit a reduced quantity of fuel to besupplied to the burner 3 which will provide a reduced flame forproducing a corresponding amount of heat. If the heat thus produced isinsufficient to main tain the room or rooms at the desired temperature,say seventy degrees, the thermostatic element 29 will thus be effectedto cause the swinging blades SI, 32 and 33 to be moved towards the leftor towards the contact screws, which ac- 5 tion will be permitted due tothe flexibility of the contact blades 32 and 33 until the contact bladeBI comes in contact with the contact screw 31 closing the circuit whichpasses from the transformer 45 through the conductors 69 and 52 to 10the motor l and thence through the conductors 53, 55 and 51 to thecontact screw 3? and thence out through the contact blades 3| and 32through the contact screw 39 and terminal bar 68 and thence through theconductors 69 and TI to the terminal '52 and thence back to thetransformer 45 through the conductors I5 ,and TI.

As this circuit through the contact screw 3! is completed, the motor Iwill be actuated to bring the pin 24 into engagement with the lug 25 formoving the valve stem 22 outwardly and bringing the valve I I into theopen position, thereby permitting a maximum amount of fuel to besupplied to the burner 3, which will produce a correspondingly increasedamount of heat for 25 again bringing the temperature in the room orrooms up to the desired or predetermined degree. As the temperature inthe room approaches the desired degree, the thermostatic element 29 willagain be actuated to return the blades to the 30 normal position whichwill break the contact between the contact blade 3I and the screw 31,thereby releasing the motor I and permitting the valve member II to bereturned to its seat I2 by the spring I3, which will again close thedirect passage through the main conduit 2 and permit only a limitedsupply of fuel to be supplied to the burner 3 through the by-pass 5.

This operation may be continued indefinitely as long as fuel is suppliedto the burner 3 and cur- 40 rent is present in the transformer 45. If,however, the temperature in the room should rise above the desireddegree, it is obvious that the thermostatic element 29 will be actuatedthereby to move the blades 3|, 32 and 33 towards the right or in adirection away from the contact screws 3?, 38 and 39 until such time asthe terminal blade 32 is brought out of contact with the terminal screw39. Prior to breaking of the circuit at screw 39 the connection betweenthe terminal screw 38 and contact blade 33 will have been brokendiscontinuing the circuit therethrough for the motor 8. After thecircuit has been broken at screw 33 and before the blade 32 is separatedfrom the contact screw 39 current for the motor 3 will be supplied fromthe transformer 45 by the current passing from the motor 8 throughconductor 63 and switch 86 which will have been closed during theinitial movement of the motor 8 by the action of the cam I9; the currentthen passes from the switch 83 through the conductor 82, terminal 83 andsupporting member 39 to the thermostatic element 29, blade 32 andcontact screw 39. As the electrical connection between the blade 32 andscrew 39 is broken by the con- 65 tinued outer movement of said blades,the motor 8 will then be released in the manner hereinbefore stated,whereupon the motor 8 will permit the spring I3 to return the valvemember II in the by-pass valve 6 to its seat I2 thus closing the valve(5 shutting off all fuel supplied to the burner 3.

As the temperature in the room is thus permitted to lower, thethermostatic element 29 will again move the blades toward the contactscrews 31, 38 and 39 until the temperature approaches the predetermineddegree whereupon contact blade 33 will again come into electricalconnection with the contact screws 38 thereby establishing a circuittherethrough for supplying the motor 8 in the manner previouslydescribed, which will cause said motor to actuate the disk l6 and pin I!for bringing said pin into engagement with the lug l8 on the valve stem[5 and move the valve member I I of the valve 6 against the action ofthe spring ii to the open position for again supplying a limitedquantity of fuel to the burner 3.

If it should be desired to manually open either the valve 4 or valve 6or both of these valves, due to the failure of current being suppliedthrough the transformer 45 to the motors I and 8 or for any otherreason, this may be accomplished by merely moving one or both of theswitch-actuating members 8'! and 91 inwardly which action will draw therespective valve member H to a partial open position, and at the sametime, close one or both of the respective switch members SI and H18 sothat these valves may be safely left in the partially opened conditionuntil such time as the current is again supplied to the transformer 65.As the current is again returned to the circuit, the motors i and 8 willbe operated thereby to bring the valves into the full open positionregardless of the position of the swinging blades Si, 32 and 33 of thethermostatic control switch 1 due to the current from the motor I, forinstance, passing through the conductor 53 and switch 9i back to thetransformer 45 through the conductor plate 94 and conductor 11.

Likewise, the current supplied from the transformer 55 to the motor 3will be returned to the transformer 45 without having to pass throughthe thermostatic switch I by passing from the terminal G l through theswitch I00, conductor bar is and conductors l5 and 11 to thetransformer. As the motors l and 8 are thus actuated to bring therespective valves into the full open position, the respectiveswitchactuating members 8! and M will thereby be released by the outwardmovement of the corresponding extensions and 93 and permitted to bereturned to the normal out position by the action of the movable contactbars 98 and ll of the respective switches 9i and Elli], after which thefuel will be automatically controlled in the manner hereinbeforeexplained by the action of the thermostatic control switch I governingthe current supplied to the motors i and 8.

It is now obvious that I have produced an automatic heat regulatingsystem in which the control valves in the main supply conduit and in aby-pass conduit will be automatically opened or closed by the action ofa temperature controlled switch independently of each other, andalthough I have shown and particularly described the preferredembodiment of my invention, I do not wish to be limited to the exactconstruction shown or to any specific construction of motors, valves orother operating mechanism, or to the exact hookthermostat control switchin said circuit adapted to control the operation of each motor wherebythe valves may be operated independently of each other, and manuallycontrolled means associated with each valve for maintaining said valvein a partial open position when the energizing circuit is discontinued.

2. In a heat-regulating system, the combination with a fuel burner, of apair of fuel conduits of different capacities adapted to supply fuel tothe burner, a valve in each of said conduits, an electric motorco-operatively associated with said valve, an energizing circuit forsaid motors, a thermostat control switch in said circuit adapted tocontrol the operation of each motor whereby the valves may be operatedindependently of each other, and manually controlled means associatedwith each valve for'maintaining said valve in a partial open positionwhen the energizing circuit is discontinued and automatically releasingthe valve when said circuit is again established.

3. In a heat-regulating system, the combination with a fuel burner and apilot burner, of a pair of fuel conduits adapted to supply fuel to saidfuel burner, a valve in each of said conduits, an electric motorco-operatively associated with each valve, an energizing circuit forsaid motors, a thermostatic control switch in said circuit adapted tocontrol the operation of each motor, and a safety pilot controlconnected in said circuit in series with said motors, and switch forautomatically causing the closing of said valves when the pilot flame isextinguished.

4. A heat-regulating system comprising in combination, twothermostatically controlled switches adapted to open and closesuccessively as the temperature varies, a burner, a pair of fuelconduits operatively connected with the burner, a valve in each of saidconduits, means for opening said valves independently of each othercomprising an electrically actuated operating means actuated by arespective switch whereby a larger or lesser predetermined steady flowof fuel will be established and maintained as determined by thetemperature affecting said switches, and additional means formaintaining one of said valves open after the circuit through both ofthe switches has been broken comprising an electrical circuit having athird thermostatically controlled switch and a mechanically operatedswitch therein, said latter switch being closed by the operating meansfor said valve during the initial movement thereof.

DONALD H. KINNAN.

